Earth boring bits such as rock bits for the oil field and mining industries have long been provided by rotary cone rock bits. The rotary cone rock bits have a bit body with an upper end adapted for connection to a drill string and typically three bit legs which extend downward from the body to provide support arms. A bearing shaft or journal extends inward and downward from each bit leg. A conventional rock bit journal is cylindrical and is rotatably received in a rotary cutter provided by a cutter cone. The cutter cone is generally mounted on each journal and supported rotatably on bearings acting between the journal and the inside of a journal-receiving cavity in each cutter cone. The cutter cones have teeth, inserts or compacts on their exteriors for disintegrating earth formations as the cones rotate on the journals, with weight applied to the rock bit. One or more fluid nozzles are often formed on the underside of the bit body. The nozzles are typically positioned to direct drilling fluid over the cones to wash away cuttings and cleanse the cutter cones.
A space between the journals and the cutters are sealed such that drilling fluids will not enter into the space and so that lubricant will be maintained between the journals and the cutters. A journal bearing seal prevents the lubricant between the cutter and the journal from being lost which will greatly increases the service life of the drill bit. Some of the interface space between the journal and the cutter is taken by the journal bearing seals, leaving less of the interface space for roller bearings located parallel to the axial lengths of the journals.